Write-once type multilayer optical disc, recording method, reproducing method, and recording device

Abstract

Manufacturing of a higher quality write-once type multilayer optical disc is facilitated. The optical disc includes a plurality of recording layers in which recording or reproduction is carried out by a blue or blue-violet laser beam of a wavelength of about 405 nm. Each of the recording layers includes a recording layer which uses an organic dye. The plurality of recording layers includes a layer in which a groove pattern around a recording mark is deformed when information is recorded, and a layer in which the groove pattern around the recording mark is not deformed when information is recorded.

1 . A write-once type optical disc comprising: 
 a plurality of recording layers in which recording or reproduction is carried out by a laser beam of a wavelength equal to or less than 450 nm, each of the recording layers including a recording film using an organic dye, wherein the plurality of recording layers includes a layer in which a groove pattern around a recording mark is deformed when information is recorded, and a layer in which the groove pattern around the recording mark is not deformed when information is recorded.    
     
     
         2 . The optical disc according to  claim 1 , further comprising one or more layers in which groove patterns made of photopolymers are formed, wherein a glass transition temperature of the photopolymer is set to 150° C. or less, or an elastic modulus is set to 3000 MPa or less at 25° C., or an elastic modulus is set to 1500 MPa or less at 100° C., and the groove pattern around the recording mark of the recording layer on the photopolymer is deformed when information is recorded by the laser beam.  
     
     
         3 . The optical disc according to  claim 1 , further comprising one or more layers in which groove patterns made of photopolymers are formed, 
 wherein a glass transition temperature of the photopolymer is set to 150° C. or more, or an elastic modulus is set to 3000 MPa or more at 25° C., or an elastic modulus is set to 1500 MPa or more at 100° C., and the groove pattern around the recording mark of the recording layer on the photopolymer is not deformed when information is recorded by the laser beam.    
     
     
         4 . A write-once type optical disc comprising: 
 a plurality of recording layers in which recording or reproduction is carried out by a laser beam of a wavelength equal to or less than 450 nm, each of the recording layers including a recording layer using an organic dye,    wherein the plurality of recording layers includes a high-to-low layer in which a reflectance of a recording mark portion is lower than reflectances of other unrecorded portions when information is recorded, and a low-to-high layer in which a reflectance of the recording mark portion is higher than reflectances of the other unrecorded portions when information is recorded.    
     
     
         5 . The optical disc according to  claim 4 , 
 wherein the high-to-low layer is a layer in which a groove pattern around a recording mark is deformed when information is recorded, and the low-to-high layer is a layer in which the groove pattern around the recording mark is not deformed when information is recorded.    
     
     
         6 . A recording method which uses the optical disc of  claim 1 , comprising: 
 recording object data in the recording layer by modulated laser power; and    recording management information of the object data in the recording layer by the modulated laser power.    
     
     
         7 . A recording method which uses the optical disc of  claim 4;  comprising: 
 recording object data in the recording layer by modulated laser power; and    recording management information of the object data in the recording layer by the modulated laser power.    
     
     
         8 . A reproducing method which uses the optical disc of  claim 1 , comprising: 
 reproducing management information from the recording layer by a laser beams of a predetermined wavelength; and    reproducing object data managed based on the management information from the recording layer by the laser beam.    
     
     
         9 . A reproducing method which uses the optical disc of  claim 4 , comprising: 
 reproducing management information from the recording layer by a laser beams of a predetermined wavelength; and    reproducing object data managed based on the management information from the recording layer by the laser beam.